The objectives of the research proposed here are (a) to establish conclusively that visual form perception occurs when a figure is exposed successively through a narrow aperture (anorthoscopic perception) where such perception cannot be explained in terms of the persistence of an image spread over the retina (b) to investigate the determinants of anorthoscopic perception under conditions where an explanation in terms of a persisting retinal image has been ruled out (c) to study the similarities and differences between several methods of creating the anorthoscopic effect (d) to investigate the basis of the various kinds of distortion of perceived form that occur under anorthoscopic conditions. Several methods of investigating these questions will be employed entailing the horizontal movement at uniform speed of an opaque surface containing a narrow aperture over an outline figure (or the movement of the figure behind a stationary aperture). An alternate method is the simulation of a figure by the vertical displacement of a small element behind the aperture. Eye-movement recordings and other methods will be used to determine whether the behavior of the eyes is such as to create a persisting retinal image during the exposure of the figure. The hypothesis guiding this research is that a retinal image of the entire figure is not necessary for anorthoscopic perception. What is necessary is stimulus information that suggests and supports the solution that the spatially adjacent regions of a figure are being successively revealed while the remainder of the figure is occluded. Perceived form--here as in more typical form perception -- is thus a function of the directional location of the parts of the figure with respect to one another. The specific shape perceived will depend upon the information used by the perceptual system to specify the rate (or direction) of exposure of the figure.